1. Field of the Invention
The present invention relates to an illuminating device, an illuminating method, a program, and a medium each of which is applied to a vehicle such as a passenger vehicle, a commercial vehicle, a bus, or the like so as to irradiate an area in front of the vehicle.
2. Description of Related Art
Various devices are proposed as an illuminating device that irradiates an area in front of a vehicle so as to improve visibility of a driver. For example, Japanese Patent Application Publication No. 2009-220636 (JP 2009-220636 A) proposes a technique in which a distance with respect to a precedent vehicle is detected and an illuminating range is gradually enlarged upward according to the distance. An illuminating device described in JP 2009-220636 A is intended to secure visibility of a driver of its own vehicle by increasing the number of situations to use a high beam, and to increase a glare-prevention characteristic in which illuminating in an illuminating range is blocked appropriately so as not to give a glare (dazzle) to an occupant in a forward vehicle, which is a precedent vehicle or an oncoming vehicle.
However, in the illuminating device described above, a boundary between an inside of the illuminating range and an outside (a light-blocking region) of the illuminating range is controlled to move proportionally based on the distance. On this account, even in a case where the precedent vehicle is a regular vehicle that is not a large-size vehicle, it is necessary to block upward illuminating in the illuminating range, and there is a possibility that the visibility of the driver, particularly with respect to indicators, cannot be increased.